The present invention relates to an electrical insulator component comprising a one-piece block of insulating fins.
Such insulator components comprise an elongate central insulating core surrounded by fins. The core may be a composite rod of glass or synthetic fibers belonging to an electrical insulator. It may alternatively be a support such as the end of a high tension cable, a cross bar, or an insulator tube for a circuit-breaker chamber. The central core is generally protected by a waterproof elastomer covering comprising a sheath and/or fins.
In a first known method of applying fins, separate fins are threaded over a previously sheathed core. The fins are then stuck together end to end. Alternatively the fins may be moulded in succession by moving a mould along said core.
In a second known method for applying fins, all the fins are simultaneously moulded about the central core. In this case, it is necessary for the mould to be in at least two parts which when joined together define a "join plane" in which the axis of the insulator component lies. The result is that all the fins show traces of said "moulding join" corresponding to the axial "join plane". These traces are in the form of a continuous straight-line path running from end to end of the insulator component. By facilitating the deposit of pollution particles, said line leads to high leakage currents and to risks of damage.
Preferred embodiments of the present invention mitigate these drawbacks.